CVE-2020-11610: 
JavaScript vulnerability analysis and mitigation

CVE-2020-11610 is a security vulnerability discovered in xdLocalStorage through version 2.0.5. The vulnerability was identified in the postData() function within xdLocalStoragePostMessageApi.js, where the function uses a wildcard (*) as the targetOrigin parameter when calling the postMessage() function on the parent object. The issue was disclosed in April 2020 and affects all versions of the xdLocalStorage library up to and including version 2.0.5 (NVD, GrimBlog).

The vulnerability stems from the implementation of the postMessage() function in the xdLocalStorage library's magical iframe component. The postData() function uses a wildcard (*) as the targetOrigin parameter, which allows any domain to receive messages sent by the magical iframe. The vulnerability has been assigned a CVSS v3.1 base score of 8.8 (HIGH) with the vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H (NVD).

The vulnerability allows any domain to load the application hosting the magical iframe and receive the messages that the magical iframe sends. This can lead to potential information disclosure as attackers could intercept sensitive data stored in the local storage. When combined with other vulnerabilities in the library, such as the lack of origin validation, attackers could potentially recover all information from local storage (GrimBlog).

The primary mitigation strategy is to replace the library with a maintained alternative that includes robust origin validation, or implement validation within the existing library. When using web messaging, it's crucial to explicitly state the targetOrigin instead of using wildcards, carefully validate the origin of incoming messages, and ensure proper validation of message data (GrimBlog).